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Biotica >> Probiotics and Prebiotics >> Probiotics

Post by DL on Sep 12th, 2006, 08:07am

Metabolic and Physiological Impact of Probiotics or Direct-Fed-Microbialson Poultry: A Brief Review of Current Knowledge
International Journal of Poultry Science 6 (10): 694-704, 2007

The following excellent article (due to space restrictions I have edited and posted below the link the most pertinent of the information on probiotics however this article does have some very good information on antibiotic usage in poultry ...history and studies etc. and is well worth the read of its contents in its entirety)

"Maintenance of antibiotic resistance is an energetically expensive process for a bacterium. Removal of antibiotics that promote resistance and seeding the bird with antibiotic sensitive probiotic organisms gradually leads to development of a bacterial population that is sensitive to antibiotics. The bacteria that are used as probiotic organisms have an ecological advantage in the gastrointestinal tract because they can multiply more efficiently than the antibiotic resistant forms that must expend extra energy for maintenance of the resistance factors rather than for reproduction. Use of probiotic bacteria that have a competitive advantage constitutes the basis of the competitive exclusion (CE) concept. However, it is important to understand that bacteria with plasmid(s) bearing antibiotic resistance factors do not simply go away. Those bacteria can survive for long periods of time before they lose resistance-bearing plasmid(s) and continue to pose a potential problem to poultry production as well as to human health. As long as there are populations of bacteria in the gastrointestinal tract that express a competitive advantage, the potential pathogens can be kept in check. "

What are probiotics?

Havenaar & Huis in't Veld (1992) modified the definition for probiotics offered by Fuller (1992), and that definition is as follows: "a mono-or defined mixed-culture of live microorganisms which, applied to animal or man, beneficially affect the host by improving the properties of the indigenous gastrointestinal microbiota, but restricted to products that (a) contain live microorganisms (e.g., as freeze-dried cells or in fresh or fermented product), (b) improve the health and well-being of animals or man (including growth promotion of animals), and (c) can have their effect on all host mucosal surfaces, including the mouth and gastrointestinal tract (e.g., applied in food, pill, or capsule form), the upper respiratory tract (e.g., applied as an aerosol), or in the urogenital tract (local application)".
The definition is very broad and provides a basis for the use of numerous bacteria and yeast for the enhancement of health and well being in host animals.
However, there might be some misunderstanding of the definition because there are other terms that describe similar concepts and these include direct-fed microbials, competitive exclusion agents, and synbiosis

Direct-fed microbials (DFM), originally described as probiotics, have been defined by the US FDA as a source of live, naturally occurring microorganisms. Under this definition, a DFM does not have to be defined with identification of each organism in the mixture. This definition then applies to use of undefined cultures from the cecal contents of healthy chickens for the expressed purpose of facilitating early colonization of the chicken's intestinal tract with bacteria that will inhibit the growth and colonization of harmful bacteria. This definition incorporated the Nurmi concept of competitive exclusion (CE). The term "competitive exclusion" was applied first in poultry by Lloyd et al. (1974) but in actuality Nurmi & Rantala (1973) and Rantala & Nurmi (1973) were the first to use the concept in poultry production.

In traditional terms, CE in poultry has implied the use of naturally occurring intestinal microorganisms in chicks and poults that were ready to be placed in brooder house. Nurmi & Rantala (1973) and Rantala & Nurmi (1973) first applied the concept when they attempted to control a severe outbreak of S. infantis in Finnish broiler flocks. In their studies, it was determined that very low challenge doses of Salmonella (1 to 10 cells into the crop) were sufficient to initiate salmonellosis in chickens. Additionally, they determined that it was during the 1st week post-hatch that the chick was most susceptible to Salmonella infections. Use of a Lactobacillus strain did not produce protection, and this forced them to evaluate an unmanipulated population of intestinal bacteria from adult chickens that were resistant to the S. infantis. On oral administration of this undefined mixed culture, adult-type resistance to Salmonella was achieved. This procedure later became known as the Nurmi or CE concept.

Synbiosis is a term that encompasses two different concepts, specifically, provision of a prebiotic and a probiotic in the same product. First, a prebiotic is an indigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon (Gibson & Roberfroid, 1995). The definition of prebiotic overlaps with that of a dietary fiber. Thus, a synbiotic must contain, as an example, fructooligosaccharides (FOS) that are naturally occurring indigestible short chain fructose polymers found in artichokes, chicory root, garlic, banana, onion, barley, wheat, rye, tomato, asparagus root, brown sugar and honey constituting the fiber used for Bifidobacteria fermentation resulting in lactic and acetic acid production that will kill acid sensitive bacteria and promote the growth of acid loving bacteria such Lactobacillus (Gibson & Roberfroid, 1995). A synbiotic relationship between a prebiotic substance and a probiotic organism suggests synergism, and in this case, provision of FOS would promote indigenous Bifidobacteria and indirectly promote Lactobacillus spp. resulting in direct benefit for the host (Schrezenmeir & de Vrese, 2001). Thus, provision of FOS will selectively promote healthful Bifidobacteria and Lactobacillus through acid production in the intestine, and these events will tip the balance of the gut microecology in favor of beneficial bacteria away from E. coli, Salmonella, Clostridium, Campylobacter, Citrobacter, and other potential pathogens. Maiorka et al. (2001) have shown that the use of a synbiotic composed of Saccharomyces cerevisiae cell walls and the spore forming Bacillus subtilis was an alternative to the use of antibiotics in broiler feed. They reported improvement in feed conversion and weight gain compared with antibiotic and control treatments at 45 days of age. Additionally, Fukata et al. (1999) looked at the use of probiotics and FOS singly and in combination in chicks and its effect on Salmonella enteritidis. At 1 day and 7 days post inoculation in both FOS and FOS plus probiotic groups, there were significantly less S. enteritidis than in the control group. In 7- and 21-day-old chicks, few changes were noted in the number of total bacteria, Bifidobacterium, Bacteroides, Lactobacillus, and E. coli in the cecal contents of treated groups compared with the control group. Low-dose feeding of FOS in the diet of chicks with a low dose of probiotic reduced susceptibility to Salmonella colonization."

"Recently, Rabsch et al. (2000) reported that S. gallinarum competitively excluded S. enteritidis. In fact, those investigators suggest that S. gallinarum was the primary agent that competitively excluded S. enteritidis early in the 20th century, but when S. gallinarum was eradicated from commercial poultry, S. enteritidis replaced S. gallinarum in its niche. Thus, competition for receptor sites in the intestinal tract is a complicated process and depends upon the ability of a species or strain to produce substances that will kill other similar or dissimilar bacteria or produce adhesins that allow that bacterium to bind to the intestinal mucosa more tightly than another bacterium. In essence, competitive exclusion occurs daily in the lives of poultry and other animal species. Therefore, it is important that the mode of action of a probiotic be determined, and it is important to use that knowledge to select organisms that will actively compete against known pathogens."

The article is continued in the following folder this forum PART II and explains the Mechanism of action of probiotics."

Probiotics and E.Coli research abstract

Re: Probiotics Prt II
Post by DL on Sep 12th, 2006, 08:33am

`Mechanism of action of probiotics

Much of our perception about the function of probiotic organisms in poultry is based upon work done in mammals, specifically humans (Kopp-Hoolihan, 2001), but the same principles might not always be the same in the avian species. Nevertheless, a delicate balance among microbes in the gastrointestinal tract of chickens provides the necessary protection that prevents invasion of a multitude of potential bacterial and protozoan pathogens that can disrupt the normal body functions of poultry. Animals and humans alike have developed an elaborate defense strategy whereby a symbiotic relationship has evolved in which commensial microorganisms actually protect and provide to the host certain benefits. Among these beneficial effects is modification of the host immune system (Table 3). In order for this mutual relationship to flourish, a complex physiological and host defense mechanism must be established. Once established, the microbiota of the gastrointestinal tract prevent colonization by other bacteria. The mechanisms used by one species of bacteria to exclude or reduce the growth of another species are varied, but Rolfe (1991) determined that there are at least four major mechanisms involved in the development of a microenvironment that favors beneficial microorganisms. Beneficial microorganisms possess certain favorable characteristics that allow for the expression of several mechanisms that prevent pathogens from colonizing the intestinal tract (Table 4). These mechanisms are listed as follows: (1) creation of a microecology that is hostile to other bacterial species, (2) elimination of available receptor sites, (3) production and secretion of antimicrobial metabolites, and (4) competition for essential nutrients.
(please refer back to the article for an excellent chart on different probiotic bacteria and their activity results)

Creating a gut microecology favorable to beneficial microorganisms

The balance among the gut microflora and the host in both mammals and birds can be challenged on a daily basis because there are potential invasive microorganisms living in our common environments. Those potential invasive microorganisms can be commensial (they live in the intestinal tract but cause no problems when there is a normal balance among microbiological species) or nosocomial (opportunistic invaders living outside the body). The water we drink, the food we eat and the air we breathe have these potential invaders present and ready to challenge the symbiotic relationship between the host and the gut microbiota. Because of this constant state of siege, elaborate defense mechanisms have evolved to cope with the potential invaders (Table 4). All food, once ingested must be subjected to gastric pH in the range of 2.0 to 4.0, which can cause a 10 to 100 fold killing of bacteria in the food being digested in the upper part of the gastrointestinal tract. The microecology of the intestinal tract is the determining factor in the viability of specific microorganisms. The production of volatile fatty acids at a pH below 6.0 is known to decrease the populations of Salmonella and Enterobacteriacea (Maynell, 1963). Disruption of the normal intestinal microbial populations with antibiotics will abolish this protective mechanism because the concentrations of volatile fatty acids produced by the intestinal bacteria will decrease and gut pH will increase toward a more alkaline range. In newly hatched chicks in commercial hatcheries, the volatile fatty acid concentration and pH are not sufficient to chemically suppress pathogens (Barnes et al., 1979, 1980a,b), and therefore, supplementation of probiotic microorganisms will be very beneficial.

A good balance of beneficial microorganisms provided through supplemental probiotic bacteria prevents adaptation of ingested and transient pathogenic microbes. It is critical to apply probiotic products as early as possible to achieve the best results in poultry (Casas et al., 1993, 1998; Edens et al., 1997a). Furthermore, some products must be provided constantly for the best results, and some products can be provided as a bolus at the time of placement for excellent but possibly transitory effects in the exclusion of certain pathogens.

As soon as a chicken hatches into an environment that is heavily contaminated by bacteria, viruses, and protozoans, it must begin to develop protective gut microflora. The gastrointestinal tract of the chicken and turkey is practically void of beneficial bacteria at the time of hatching, and in some cases, a period of five to seven days after hatching is required to establish a healthy population of lactic acid bacteria in the gut. Because the lactic acid bacteria can survive and grow in both aerobic as well as anaerobic environments, they become the dominant bacteria throughout the gastrointestinal tract from the crop through the large intestine. Due to the abundance of substrates, the lactic acid bacteria thrive in the gut and produce lactic acid and hydrogen peroxide in addition to antibacterial substances such as bacteriocins, reuterin, nisin, or lactococcins (Table 5) all of which are known to have inhibitory effects on enterobacteriacea genera such as E. coli and Salmonella spp., and other bacteria such as Staphylococci spp., Clostridium spp., Listeria spp. both in vitro and in vivo.

Before the development of lactic acid bacterial populations in the gut, the newly hatched chicken begins to pick-up coliforms and streptococci from its environment. These bacteria can be beneficial or they can be pathogenic. Because there is a delay in the development of a population of beneficial bacteria, the potential for colonization by pathogenic strains can be elevated, but usually, if the dam has done her job properly, maternal antibodies can help to prevent pathogen colonization. Nevertheless, under normal conditions, a three to five week period is required for development of a stable population of gut associated bacteria, and it is in the ceca where the greatest numbers reside (Sarra et al., 1992).

In the ceca, an anaerobic environment develops and favors the growth of organisms such as Bifidobacterium spp. and Bacteriodes spp. In this strictly anaerobic environment those named bacteria along with other lactic acid bacteria create a microecology that can be characterized by an acid pH resulting from the production of volatile fatty acids (acetic, butyric, propionic, and lactic acids) and antimicrobial substances (Table 5) that effectively exclude or kill many different pathogens."

Part III explains the mechanism of
Elimination of available receptor sites
and why it is important to provide the highest number of probiotic bacteria as possible and as soon as possible to achieve the best results in the control of pathogenic bacteria.

Re: Probiotics Part III
Post by DL on Sep 12th, 2006, 08:39am

"Competition for essential nutrientes

Competition for available nutrients as a means to control intestinal bacterial populations is probably not the most effective means for CE. Rolfe (1991) indicated that there were many environmental factors that come into play that either enhance availability of nutrient from the diet of the host or through manipulation of dietary ingredients that enhances the growth of certain microbial populations which may result in exclusion of other bacterial species. A normal balance of bacteria in the gastrointestinal tract is capable of utilizing all of the potential carbon sources in the environment (Freter et al., 1983). It has been shown that by manipulating the lactose concentration in the diets of chicks and poults, one can selectively provide an advantage for the enhancement of L. reuteri (Casas et al., 1993, 1998). Behling & Wong (1994) gave day old chickens an E. coli (O75:H10) with 2.5% dietary lactose and found that there was significant protection against S. enteritidis. Using this method of deduction, provision of certain types of feed ingredients may also enhance the presence of certain other types of gut microflora. Oyofo et al. (1989a) studied in vitro the effect of mannose on the colonization of S. typhimurium in chickens. They incubated intestinal sections, isolated from one-day-old chickens, with either radiolabeled-S. typhimurium strains ST-10 and ST-11 (mannose-sensitive), or strains Thax-1 and Thax-12 (non-yeast-agglutinating strains), or with only phosphate buffered saline in the presence of D-mannose, arabinose, methyl-a-D-mannoside, or galactose. The incubation of intestinal sections with bacteria and mannose resulted in a significant reduction of S. typhimurium adherence. This same group of investigators also confirmed this result in vivo (Oyofo et al., 1989b). When they gave mannose orally to chickens and subsequently challenged the chickens with S. typhimurium, they reported that mannose inhibited S. typhimurium colonization to the intestine. In a different study, Oyofo et al. (1989c) tested other carbohydrates such as dextrose, sucrose, and maltose with little if any inhibition of colonization.

Since bacteria use lectins on their cell surface to bind to mannan on the intestinal epithelial cells to initiate attachment and colonization, it has been suggested that mannanoligosaccharide (MOS), a yeast cell wall derivative, might inhibit the colonization of bacteria to the intestine by binding to bacterial mannan-binding lectin. Spring et al. (2000) report that MOS (BioMos, Alltech, Inc., Nicholasville, KY USA) acts to bind and remove pathogens from the broiler chicken intestinal tract and stimulate the immune system. Swanson et al. (2002) investigated whether supplemental BioMos influenced microbial populations in dogs. Dogs treated with BioMos were shown to have a higher number of Lactobacilli that produce lactic acid as their major end product during fermentation of carbohydrates. Not only does BioMos inhibit the attachment of some enteropathogenic bacteria to the intestinal epithelium, but it also alters the numbers of the broiler chicken intestinal microflora (Spring et al., 2000). Fernandez et al. (2002) investigated the effect of BioMos on the number of microflora in chickens and showed that there was increased numbers of Eubacterium spp. and Enterococcus spp. while the number of Bacteroides spp. were found to be decreased. The increased number of these bacteria probably indirectly inhibited the colonization of pathogenic bacteria by preventing their attachment to the gastrointestinal epithelial cells. In a study in young turkeys fed BioMos, Bradley et al. (1995) observed improved body weight and altered ileum morphology. In the ileum, the crypt depth was less and the number of goblet cells per mm of villus were increased significantly. Edens et al. (1997a) reported an increase in goblet cell numbers and mucus secretion in the intestine of chickens challenged with S. typhimurium, but this condition was corrected by the application of a probiotic.

A recent study in mice has shown that Saccharomyces cerevisiae var. boulardii in mice stimulated secretory IgA production (Rodrigues et al., 2001). Saccharomyces cerevisiae NCYC 1026 is the basis for BioMos. BioMos also has been reported to exert an immuno-stimulatory characteristic. The levels of IgG in serum and IgA in bile and cecum were elevated in turkeys and rats, respectively, fed with BioMos compared to control (Kudoh et al., 1999). In addition, pigs fed BioMos had an increased number of blood lymphocytes (Spring & Privulescu, 1998). The elevated levels of IgA may be associated with increased rate of bacterial clearance via antibody-mediated phagocytosis.

Use of prebiotics such as fructooligosaccharide (FOS) can serve as a fiber source for certain microbial populations and enhance production of organic acids in the gut. Furthermore, use of mannanoligosaccharide (MOS) can bind to receptors on many bacterial pathogens themselves preventing their attachment to epithelial binding sites and modify intestinal commensial microorganisms.

Stress factors affecting probiotic performance

Use of probiotics for poultry production is not without certain risks and limitations. There are many stress factors in the environment of newly hatched poultry species that could reduce the effectiveness of the maternal antibody defense mechanism and normal colonization of the gut by beneficial microorganisms effectively allowing the colonization of pathogens during the early post-hatch stage. This seems to be somewhat ironic because there is evidence that probiotics can limit the consequences of exposure to stressors of many types. Some of the stress factors and causes of the stress are listed in Table 6.
(refer back to article link for this chart)
The factors listed in Table 6 show that there are high probabilities that newly hatched chickens and turkeys will face a situation in commercial as well as in experimental settings that will alter the development of natural gut-associated beneficial microorganisms. The primary factor affecting this development can be the feed source and quality. Under-formulated diets result in nutritional stress and decrease the growth of beneficial organisms. Molds and mycotoxins further add to the problem of nutritional stress and can cause the loss of essential nutrients for the gut microbes. However, nutrient degradation may be the most important factor to affect the gut microbes. This can be caused by numerous factors such as oxidized dietary fat and lipid peroxidation, vitamins, amino acids and proteins also influence the populations of beneficial organisms in the gut, but in this era of concern about microbial contamination of feed, higher and higher pelleting temperatures in feed manufacturing causes the destruction of not only pathogenic but beneficial organisms as well. The only probiotic organism that can tolerate relatively high temperatures associated with the pelleting of chicken and turkey feed are the spore-forming Bacilli. All other probiotic organisms will die as a result of pelleting. Therefore, most probiotics must be applied via drinking water or as a top dressing to pelleted feed.

Exposure of chickens and turkeys to extreme conditions in the environment can induce nonspecific stress responses leading to depressed immuno-responsiveness that will influence gut microbial populations. Unfortunately, the depression in the production of immunoglobulins, specifically IgA, tends to influence pathogen growth more than beneficial microbes. Many managerial stressors such as beak and claw trimming and other hatchery processes such as vaccinations and handling for sexing and high population densities after placement contribute to immuno-suppression in poultry. However, we always come back to antibiotic use/abuse in the poultry industry. Over use of antibiotics can have very negative effects in the young bird. In some commercial operations, it is common practice to add high levels of antibiotics to the first feed given to chickens and turkeys. Usually, in the USA, this medicated feed can be available for as long as 10 days after placement. This medicated feed is replaced then with feed that does not contain antibiotics. Within a few days after the new feed has been provided, the chickens and turkey poults may begin to refuse feed and to develop signs of an enteritis that is now frequently called "off-feed enteritis". When the intestinal tracts are analyzed for bacterial populations, there are usually low numbers of beneficial bacteria such as Lactobacilli and extraordinary numbers of potentially pathogenic E. coli, Salmonella, Clostridium, and others. Naturally, the producers revert to an antibiotic treatment, and sometimes they also think about the possibility of a probiotic. Unfortunately, there is a limited number of products that can be used along with certain antibiotics. Among the commonly used antibiotics, Bacitracin has been shown to have the least influence on Lactobacilli (Casas et al., 1998). Therefore, we as producers of commercial poultry have created a situation that appears to be feeding upon itself and continuing to grow. The end result of prolonged use of antibiotics is antibiotic resistant bacteria and inhibition of growth of beneficial bacteria in the intestinal tract of poultry and other livestock.

Nevertheless, we can break this chain of events by (1) reducing antibiotic use on a prophylactic basis, and (2) we can develop a managerial plan that incorporates the use of probiotics into flock management programs."

Please refer back to article link for
Performance of poultry given probiotics and the article references.

Re: Abstract of Study/product
Post by DL on Jan 7th, 2007, 03:52am

A review of probiotics (2006)


some more info on this product (manufacturers site U.K.):

Re: Probiotics
Post by DL on Oct 29th, 2008, 10:51am

"TP345 Optimising feed inclusion levels of a multistrain probiotic in broiler nutrition. K. C. Mountzouris1, P. Tsirtsikos1, R. Beltran*2, M. Mohnl3, G. Schatzmayr3, and K. Fegeros1, 1Agricultural University
of Athens, Department of Animal Nutrition, Athens, Greece, 2BIOMIN USA Inc, San Antonio, TX, 3BIOMIN GmbH, Herzogenburg, Austria.
Probiotics are live microbial feed supplements that belong to zootechnical feed additives. An assessment of current literature indicates that apart from microbial species composition, animal response to probiotics
could be dose related. The aim of this work was to investigate the feed optimum inclusion
level of a commercial multistrain probiotic (Biomin® Poultry5Star, BIOMIN GmbH) in broiler nutrition. A total of 525 one-day-old male Cobb broilers were allocated in 5 experimental treatments for 42 days.
The experimental treatments received a corn-soybean basal diet (BD) and were: C (BD no additions), P1 (BD + probiotic at 108 CFU/kg feed), P2 (BD + probiotic at 109 CFU/kg feed), P3 (BD + probiotic at 1010 CFU/kg feed) and A (BD + avilamycin at 2.5 mg/kg feed). Each
treatment had 3 replicates of 35 broilers. Body weight (BW), feed intake (FI) and feed conversion ratio (FCR) was determined on weekly and overall basis. Overall, treatment P1 performed better than the rest in terms of BW gain and FCR. Treatment A (2,230 g)
was intermediate and not different from P1 (2,293 g) or from P3 (2,167 g), P2 (2,163 g) and C (2,165 g). FCR value for treatment P1 (1.78) was significantly better from treatments C (1.86) and P3 (1.88).
Our study indicates that probiotic inclusion at 108 CFU/kg feed, could be optimum for enhancing growth promotion."